One of the more debilitating hand conditions is trigger finger or thumb. In this painful condition, the tendons of the finger or thumb cannot bend or straighten smoothly due to thickening, swelling, or nodules in the tendon, its synovial sheath, or the connective tissue bands around the finger called pulleys. Trigger finger can be an overuse syndrome or a result of another systemic problem.

As we will see, the simple process of grasping objects requires a complex anatomical and mechanical interface to make the fingers function with precision grip. Trigger finger is not as common as other wrist and hand problems, like carpal tunnel syndrome, but can be incapacitating and painful. When the signs and symptoms are recognized early, less invasive treatment may be successful and prevent the need for surgery.

Anatomical Background

Understanding trigger finger starts with comprehending the unique system of tendons and connective tissues in the fingers and thumb that act like ropes and pulleys. Grasping objects requires the joints bend in flexion. The finger and thumb flexor tendons run along the anterior surface of the fingers or thumb. These tendons are tethered close to the bones by connective tissues referred to as pulleys.

Finger Pulleys. In the fingers, the pulleys are found at eight locations from the metacarpophalangeal (MCP) joint to the distal phalanx. The thumb is generally considered to have three primary pulleys, although some recent anatomical studies have described a fourth pulley in the thumb.¹ Let’s take a look at these pulleys, how they work, and their role in trigger finger.

Annular Pulleys. There are five pulleys in the fingers, called annular pulleys, named A1 through A5 (Image 1). The A1, A3, and A5 pulleys are smaller and considered minor pulleys (primarily due to size, not importance). The A2 and A4 pulleys are larger and are sometimes called the major pulleys. The A1, A3, and A5 pulleys are located at the MCP, the proximal interphalangeal (PIP) joint, and the distal interphalangeal (DIP) joints, respectively. The A2 and A4 pulleys are located in the middle of the proximal and middle phalanx, respectively (Image 1). The thumb contains just three primary pulleys: The A1 and A2 pulleys are like those of the fingers and an oblique pulley sits between them (Image 2).

Cruciate Pulleys. In the fingers, a second set of connective tissue pulleys, called cruciate pulleys, give additional support and stability to the tendons. The term cruciate means cross, and you can see by their structure where they get their name (Image 1). The cruciate pulleys are much smaller than the annular pulleys. There are three cruciate pulleys, designated as C1, C2, and C3. Their role in improving the flexor tendon’s angle of pull is not significant, so if they are damaged, finger movement is not impaired as much.

With all these connective tissues crossing over the tendons, there is significant friction between the tendon and the pulleys. The tendons are enclosed in a synovial sheath to reduce adverse friction. The sheath is in contact with the connective tissue pulleys, and the tendon slides back and forth inside the sheath, so it does not rub against the pulleys. However, pathologies of these tendons and their surrounding synovial sheaths may still develop from excessive friction or other factors. Trigger finger/thumb is one of those situations.

Pathophysiology

Trigger finger is also called stenosing tenosynovitis. The term stenosing means narrowing and refers to the narrowing of the space for the tendon inside the sheath due to fibrous adhesion and inflammation. Tenosynovitis refers to inflammatory irritation between the tendon and the surrounding synovial sheath. Stenosing tenosynovitis develops because of excess irritation between the tendon, sheath, and the flexor pulleys in the finger.

Trigger finger generally develops when inflammation and swelling occur at the interface between the tendon and one of the pulleys, usually at the A1 pulley. Inflammation occurs in the tendon, the sheath, the connective tissue pulley, or a combination. The thickening prevents the tendon from gliding smoothly through the pulley, resulting in pain, limited movement, and strange sensations.

A fibrous nodule can also develop on the tendon that prevents the tendon from sliding underneath the pulley. With force, the nodule can pop underneath the pulley. The sudden motion and popping of the tendon nodule are like pulling a trigger, which is where the condition gets its name. It is usually quite painful when the nodule pops back and forth under the pulley as well.

There is about a three-to-one ratio of females to males who develop this condition, and it is most common in people in their 50s and 60s.² It is more frequent in the thumb and ring finger, though it can also occur in the index finger and long finger. People are more likely to develop this condition in their dominant hand, which strengthens the idea that some of the problem may be related to chronic overuse and physical load on the finger tendons. Forceful gripping, blunt trauma, or repetitive finger/thumb movements also seem to be related to developing the condition. It affects about 2–3 percent of the general population.

In addition to biomechanical causes, there seems to be a strong correlation of trigger finger with various metabolic conditions, particularly diabetes, affecting up to about 10 percent of that population.³ Other metabolic challenges that can also play a prominent role in trigger finger development include rheumatoid arthritis, Dupuytren’s contracture, osteoarthritis, de Quervain’s tenosynovitis, osteoarthritis, hypothyroidism, and carpal tunnel syndrome. The nature of the relationship of these conditions to trigger finger is not very clear, other than they all involve systemic inflammation. Trigger finger/thumb can also be a combination of biomechanical or metabolic factors.

Assessment

During your initial history, the client is likely to report pain and stiffness, with limited motion in bending the finger or thumb in flexion. It may also hurt as they fully straighten the digit. They may also report popping or grating sensations with movement. If the condition is advanced, they may also report the joint getting stuck in either flexion or extension. Movement limitations are likely, with a possibility that the digit cannot bend or straighten at all.

There is likely to be an increased degree of tenderness near the MCP joint. It will be helpful to ask questions about any existing metabolic challenges, such as diabetes, hypothyroidism, rheumatoid arthritis, or any of the other metabolic factors we know may be related. There may not always be evidence of any specific overuse, but ask questions to identify if there have been any significant increases in biomechanical stress of the fingers or thumb.

Swelling, a bump, or a protrusion may be palpable if a tendon nodule has developed. If the condition is on one side, you will feel the difference in size between the affected and unaffected side. It may be challenging to make this comparison if both sides are involved, but enlargement around the joint is common. The area in which the tendon nodule has developed is also likely to be painful with palpation. Use caution when applying pressure, as the pain can be sharp and sudden when the damaged tissue is touched.

Both finger/thumb passive or active flexion and extension are likely to be painful. Active movement may be more painful because of the greater load on the affected tissues. There may also be pain during resisted finger flexion or extension (manual resistive tests) if a nodule is encountering the connective tissue pulley. In most cases, a nodule and restriction will be on the palmar side of the fingers, so flexion is affected more than extension. If the condition is seriously advanced, the finger may be stuck in partial flexion or stuck in extension, and the client may be unable to move it past that point. It is also common for the client to report grating sensations (crepitus) during finger or thumb movements.

There is no gold standard or definitive clinical test to diagnose trigger finger. Identifying the condition is based primarily on a detailed clinical examination. Ultrasound is frequently used as a diagnostic tool to measure the thickening of the affected tendon sheath, which may help identify the condition. Ultrasound evaluation would be used in conjunction with a detailed physical exam to identify the likelihood of trigger finger existing.

Treatment

The preferred treatment for trigger finger starts with conservative strategies. Unfortunately, there are no firmly established conservative treatments that show high success. Conservative treatment usually begins with splinting the affected joint region to decrease the load on the tendon. Activity modification is also crucial at this point to keep from overloading the tendons and causing further inflammatory aggravation.

Fibrous adhesions can develop between the tendon, sheath, and connective tissue pulley and appear to be a primary factor in the condition’s perpetuation. Gentle movement within the tolerable range is usually encouraged so that additional tissue adhesion does not develop. Sometimes ice is recommended to decrease inflammatory activities, but heat might help increase pliability of the affected tissues and encourage a greater degree of movement.

Friction Massage

It is unclear what role massage can play in addressing trigger finger. It is likely to be more helpful early on before significant tendon nodules and more extensive fibrous adhesions have developed between the tendon, sheath, and overlying connective tissue pulley. There are a few studies that refer to massage being helpful in the early stages. However, they do not specify what techniques or methods of massage are likely to be most helpful.⁴

Friction massage is often used to address similar problems such as tenosynovitis and tendinosis. The idea is that friction helps reduce adhesions between adjacent tissues and encourages greater mobility. This effect might occur in massage treatment of trigger finger to some degree as well. However, more research should be done in this area to test this theoretical idea.

Friction massage should not be detrimental as long as it is performed within the client’s comfort and pain tolerance. In addition, teaching the client to do self-massage on the affected areas may be helpful because they can apply this technique in just a few minutes several times a day.

Friction techniques are likely to be more effective when performed repeatedly as opposed to a once-a-week treatment. This is an instance in which client education and self-massage strategies can be a critical part of therapy.

Corticosteroid Injection

If initial conservative treatments are ineffective and the condition is in its early and mild stage, the next treatment usually attempted is corticosteroid injection. Injections are given in the region of the affected tendon and pulley to help reduce inflammation, decrease pain, and encourage movement. Steroid injections have shown some promise with mild conditions (Stages 1 and 2), but there is limited research to support this treatment and several side effects.

Generally, the doctor gives the patient an initial injection and then evaluates if improvement follows. If the patient has no improvement, further injections are not recommended. If there is some improvement, a second shot may be suggested, spaced about six months later. Some studies show improvement to be too limited to warrant a third shot, so only two injections are recommended.⁵ There is generally no improvement with corticosteroid injections if the trigger finger results from diabetes, rheumatoid arthritis, de Quervain’s tenosynovitis, osteoarthritis, or hypothyroidism.

Initial side effects of corticosteroid injections can include additional swelling, discoloration, and fat atrophy and infection at the injection site. Blood sugar may be elevated for up to 10 days, so anyone with insulin-related diabetes should consult their doctor. Longer-term effects can sometimes include tendon weakening.

Extracorporeal Shockwave Therapy

A relatively new treatment for trigger finger/thumb has emerged in the last few years. Extracorporeal shockwave therapy (ESWT) is effective with various conditions, including kidney stones, plantar fasciitis, and other soft-tissue disorders. In this treatment, a high-intensity shockwave is generated by a small device and applied to the affected area. The shockwave is thought to break up adhesive tissue and accelerate the healing response.⁶ The ESWT treatment is still relatively new but shows promise for those who do not want injections and may not be ready for surgery.

Surgery

If other conservative treatments have not been effective, surgery is usually the next step. There are two primary surgical procedures performed to address trigger finger. The first is called percutaneous release and generally involves inserting a needle into the affected area to probe and break up the fibrous adhesions preventing effective movement. Because it only involves the needle incision, percutaneous release is considered less invasive, and the recovery time is shorter. However, because the physician cannot see the tissues being worked on, this treatment can be challenging. Ultrasound can be used to help guide the location of the needle, making the treatment more exact. 

The other surgical procedure is called an open release and involves creating a small incision in the finger over the affected pulley. The pulley or tendon sheath is usually cut to allow the tendon to move underneath the pulley freely. Allowing increased movement can decrease the inflammatory response and allow the person to get back to normal activities. Both of these surgeries are minimally invasive and usually have a moderately short recovery time.

Conclusion

Trigger finger can be a debilitating and painful condition. It is also something massage therapists should be aware of because it could be a career-limiting injury. There is no gold standard for effective treatment, and many people prefer to investigate conservative options first. As a result, there is a serious need for more exploration into the potential of massage to address this condition. There is an excellent physiological argument for why massage, mobility, and safe, protected movement can all work together, especially in the early stages, to prevent the condition from developing further. Soft-tissue mobilization strategies have the potential to reduce health-care costs, long-term impairment, and the need for invasive procedures.

Notes

1. Brian Zafonte, Dora Rendulic, and Robert M. Szabo, “Flexor Pulley System: Anatomy, Injury, and Management,” Journal of Hand Surgery 39, no. 12 (December 2014): 2,525–32, https://doi.org/10.1016/j.jhsa.2014.06.005.

2. Angelo V. Vasiliadis and Iraklis Itsiopoulos, “Trigger Finger: An Atraumatic Medical Phenomenon,” Journal of Hand Surgery 22, no. 2 (February 2017): 188–93, https://doi.org/10.1142/S021881041750023X.

3. Amber Matthews et al., “Trigger Finger: An Overview of the Treatment Options,”  Journal of the American Academy of Physician Assistants 32, no. 1 (January 2019): 17–21, https://doi.org/10.1097/01.JAA.0000550281.42592.97.

4. Amber Matthews et al., “Trigger Finger: An Overview of the Treatment Options.”

5. Benan M. Dala-Ali et al., “The Efficacy of Steroid Injection in the Treatment of Trigger Finger,” Clinics in Orthopedic Surgery 4, no. 4 (December 2012): 263–68, https://doi.org/10.4055/cios.2012.4.4.263.

6. P. Yildirim et al., “Extracorporeal Shock Wave Therapy Versus Corticosteroid Injection in the Treatment of Trigger Finger: A Randomized Controlled Study,” Journal of Hand Surgery 41, no. 9 (January 2016): 977–83, https://doi.org/10.1177/1753193415622733.

 Whitney Lowe is the developer and instructor of one of the profession’s most popular orthopedic massage training programs. His text and programs have been used by professionals and schools for almost 30 years. Learn more at academyofclinicalmassage.com.